Laminated paper yarns and fabrics



Feb. 14. 1956 D. W. LIGHT 2,734,532

LAMINATED PAPER YARNS AND FABRICS, mcwnmc THE SAME Filed July 31, 1951 United StateS Patent" LAMINATED PAPER YARNS AND FABRICS INCLUDING THE SAME Donald W. Light, Wayland, Mass.

Application July 31, 1951, Serial No. 239,518

2 Claims. (Cl. 139-420) The present invention relates to yarns to be used particularly as weft and stutter warp yarns for carpets and similar fabrics, but can also be used to advantage in other weaving, serving, and stufling or spacing applications. Although less expensive than the textile and bast fibre yarns they replace, the acceptance of the paper yarns here- 2,734,532 Patented Feb. 14,1956

' but it is readily apparentthat the arrangement is adaptable .to any desired number of plies, the number of which will be dependent upon the thickness of yarn desired and the weight or thickness of the paper constituting the plies.

. There are, of course, numerous variations possible inthe arrangement of the devices coating the layers and laminating them, but it is believed that Fig. 1 clearly illustrates the basic steps and the principles involved. Fig. 1 shows a continuous production of yarn from a web, but it is evident that such production can be split up into anumber of separate operations if desired. The heavy lamitofore available for use in carpets and other applications has been slow due to their low strength, stiffness or wiriness, tendency to kink or twist, and slipperiness.

Heretofore such yarns have been made by slitting paper into ribbons that simulate textile fibre slivers and twisting these into a yarn, following closely the traditional methods and using the same type of equipment as in the textile industry. In the attempt to adapt paper to this process and at the same time alleviate theserious objections enumerated above, much experimenting has been done and some improvements have been effected, but the basic faults remain. So far as I know there has been no attempt to develop a process and a yarn designed around and taking advantage of the inherent characteristics of paper rather than trying to adapt it to the established textileyarn processes.

The present invention utilizes the wide widths in which paper is produced, for I have discovered that a more satisfactory yarn can be made by laminating plies of suitable paper with a flexible adhesive and then slitting the wide paper mass into strips whose width is preferably about equal to the thickness of the laminated sheet'so that preferably the yarn has a square cross-section. My present invention also includes the novel fabric made with such yarn. My invention also includes fabrics and particua: mess of the yarns B thus formed will be about equal and larly carpets in which some of the yarns and particularly stuffer warps are or may be rectangular in cross section so that they take the place of two or more twisted yarns laid side by side.

The invention will be readily understood from the following description taken in conjunction with the accompanying drawings in which:

Fig. 1 is a diagrammatic view of a machine by which the yarn may be produced.

Fig. 2 is a section on line 22 of Fig. 1 after slitting.

Fig. 3 is a yarn greatly exaggeratedin size to illustrate its construction.

Fig. 4 is a yarn having somewhat different dimensions. Fig. 5 is a section of a piece of carpet in which the yarn embodying the invention is employed as a weft.

Fig. 6 is a section of another carpet in which a yarn of essentially square cross section is used as a weft; and

Fig. 7 is a section of the carpet shown in Fig. 6 and over drums 15 that are heated if emulsion type adhesiveis used and requires drying, or that are cooled if .a hot taken at right angles, yarn of rectangular cross section;

nated sheet A can be built up by several separate laminating operations; and the slitting can be done separately or can be done by stages. Any machine or procedure may be adopted which will superpose several plies of paper, secure them together, and cut strands therefrom.

The laminated sheet A produced by the machine shown in Fig. 1 is-shown in Fig. 2 and the slits separating the sheet into yarns B are spaced so that the width andthickconsequently the yarn will be about square in cross section'as shown in Fig. 3. In Fig. 4 is shown a yarn which is wider than its thickness and is useful particularly for stutter warps in carpets where the stufiing or spacing characteristics are more important than the yarns flexibility. More than one ordinary textile or twisted yarn may be replaced thereby.

As shown in the drawings, the thickness of the yarns B at least approximate their width so that the yarns have substantial thickness in comparison with their width. The yarns B are thus of suitable body and dimension to 'replace conventional filler or stulfer yarns in fabrics such as carpets as opposed to strips of material which are thin compared with their width and which are useful for plaiting mats and the like but are not suitable for stuifer yarns for fabrics such as carpets.

In the manufacture of yarn embodying the invention various types of paper can be used but I employ preferably a high quality kraft paper of maximum fibre orientation and strength in the machine direction. Aside from a high machine direction tensile strength such a paper is generally characterized by a higher ratio of cross direction to machine direction tear, greater porosity, and lower density than the usual kraft paper. Kraft paper of almost any weight up to one hundred and fifty pounds per ream might be used but I prefer paper within the range of twenty-five to sixty pounds per ream, and more particularly about forty pounds per ream.

One advantage of the present invention is that it can make use of the more economical heavier weight papers that are not adaptable for twisting into finer gauge yarns because of the limitation of handling the narrower widths of ribbons entailed.v Where yarn with high wet strength is'required, high wet strength paper may be employed, for instance, treated with melamine-formaldehyde, ureaformaldehyde, or other suitable resins wellknown to the paper making art.

The adhesive employed may be either an'emulsion or V sion compounded with dibutyl phthalate plasticizer. In fact, asphalt adhesives modified with rubber or synthetic copolymers to improve flexibility are satisfactory where the color and solvent susceptibility of the asphalt are not objectionable. It is desirable that lamination of the paper webs with any of these adhesives be accomplished with a minimum of saturation of the paper by the adhesive in order to obtain maximum flexibility. The flexibility of the adhesive and the bond, has a direct bearing on not only the yarns flexibility but also upon. its knot or cut strength. When folded or knotted the plies will conform or adjust at areas of high stress when a flexible adhesive, is used, whereas with conventional inflexible adhesives the plies will shear and the yarn will. have poor strength when distorted.

A satisfactory yarn is made with twelve plies of twentyfive pounds-per ream kraft paper and a rubber latex base adhesive. This yarn had an average thickness of about .031' inch and wasslit to have a width of .03 inch. The yarn measured about eight hundred and forty yards per pound. 7

When such a yarn is used for the weft H of a woven fabric, such as that indicated in Figs. and 6, it will be found. to be particularly satisfactory since the other threads and yarns pressed against it in the woven structure tend to indent or form depressions in the edges of the square laminated yarn with the result that abnormal slippage between yarns is eliminated and the whole fabricstructure is stabilized. Such weft yarns have good strength and Wearing qualities and sulficient bulk to give a full plump appearance to the fabric. In Fig. 7 I have shown how a single stufier warp G of rectangular cross section may be used in place of two or more twisted stuffcr warp yarns. the yarns embodying my invention shown in the drawings and foregoing description are merely by way of illustration, since the yarn is capable of many other uses.

I claim:

1. A woven fabric comprising a warp of conventional fibre yarn, aweft including untwisted yarn of quadrilateral cross-section having sharp corner edges and flat sides, said untwisted yarn being composed exclusively of several superposed layers of paper secured to each other solely by a, flexible. adhesive-and said warp being drawn across the said sharp corner edges of the weft.

2. A woven fabric comprising a warp and a weft and including conventional fibre yarns and untwisted yarns of quadrilateral cross-section having sharp corner edges and flat sides, said untwisted yarns being composed of several superposed layers of paper secured to each other solely by a flexible adhesive and said conventional fibre yarns being drawn across said sharp edges of said untwisted yarns.

References Cited in the file of this patent UNITED STATES PATENTS 1,810,438 Rado June 16, 1931 1,829,299; Rosenstein Oct. 27, 1931 1,852,451 Everett Apr. 5, 1932 1,913,397. Knecht June 13, 1933 2,492,670- Underwood Dec. 27, 1949 It will be understood that the particular uses of 

1. A WOVEN FABRIC COMPRISING A WARP OF CONVENTIONAL FIBRE YARN, A WEFT INCLUDING UNTWISTED YARN OF QUADRILATERAL CROSS-SECTION HAVING SHARP CORNER EDGES AND FLAT SIDES, SAID UNTWISTED YARN BEING COMPOSED EXCLUSIVELY OF SEVERAL SUPERPOSED LAYERS OF PAPER SECURED TO EACH OTHER SOLELY BY A FLEXIBLE ADHESIVE AND SAID WARP BEING DRAWN ACROSS THE SAID SHARP CORNOR EDGES OF THE WEFT. 